Amazon didn’t immediately respond to requests for comment, and it’s unclear whether the shortage is due to a surge in demand or supply-chain problems — or whether the company has stopped shipping the Kindle 2 in anticipation of a Kindle 3.

Peter Kafka also had an inkling that this might have something to do with a shiny new version of the Kindle on the horizon: “Alternate theory: Amazon (AMZN) has stopped selling the Kindle because it’s about to release a new one jam-packed with astounding features.” Kafka also pointed out that you can still buy the Kindle DX, which has a larger screen. That one will cost you, though. So if you don’t want to empty your wallet you are going to have to buy (as the Journal points out) a different e-reader, or one of those things with pages made from paper.